NASA plans a series of missions to answer the questions, "Where did we come from?" and
"Are we alone?" Telescopes in space and down on Earth will look out beyond our Solar System to the vicinity of nearby stars for Earth-like planets that may harbor life.

SIRTF, scheduled for launch in January 2003, is the fourth and final mission under NASA's Great Observatories program, this telescope will use infrared, or heat, radiation to study the early universe, old galaxies and forming stars, and detect and characterize dust disks around stars where planets may be forming. This information may help identify potential targets for subsequent planet-finding missions. SIRTF is managed by JPL.
Learn more about the SIRTF mission

French COROT Telescope

COROT

The French space agency CNES will send up a small space telescope in 2004 to detect planets larger than Earth on the basis of their transits.

The 10.6-inch-diameter telescope in an orbiting satellite above the blurring effects of Earth's atmosphere is named COROT forCOnvection, ROtation and Transits. The telescope will study some stars for five months to build strong signals from which exoplanets then can be found.

NASA plans to launch a space telescope called Kepler to Earth orbit in 2007 to monitor 100,000 stars for four years.

Kepler will gaze across lightyears of space in search of rocky Earth-size planets that can sustain life around other stars in solar systems like our own.

With a continuous fixed stare through its a 37-inch-diameter aperture, the telescope will try to see transits of planets, which occur when a planet crosses the line of sight between us and the planet's parent star.

The Kepler astronomer team calculates it may find 640 terrestrial planets.

Finding many planets would suggest to the astronomers that life could be widespread across our Milky Way galaxy. On the other hand, if very few planets are found, then astronomers might conclude that life is rare.

Kepler. scheduled for launch in 2007, will search for planets with the "transit" method. A one-meter diameter (39-inch) telescope equipped with the equivalent of 42 high quality digital cameras will steadily monitor 100,000 stars, looking for planets that cross the lines-of-sight between Kepler and their parent stars. The transiting planets reduce the star's brightness by a small fraction for a few hours. The periodic signature of these "transits" can be used to detect Earth-like planets and determine their sizes and orbits.
Learn more about the Kepler mission

Space Interferometry Mission

NASA's Space Interferometry Mission (SIM) would be launched in 2009 to hunt for Earth-style planets around other stars.

SIM would fly away from Earth to orbit the Sun on a path following Earth's orbit. Using the technique of interferometry, SIM would incorporate multiple telescopes to gather light, then combine and process the light to yield new data normally obtained only by larger telescope.

SIM TelescopesNASA

SIM also would locate and measure distances to stars and other celestial objects across our Milky Way Galaxy.

SIM, managed by JPL, will very precisely measure the distances to stars throughout our Milky Way galaxy and will detect the wobble of stars due to the gravitational tug of orbiting planets. The mission will reveal whether the architecture of planetary systems like our own, with rocky planets in the habitable zone, is common or rare in our galaxy. The mission will pinpoint specific nearby stars for subsequent planet-finding and lifefinding missions.
Learn more about the SIM mission

Eddington

The European Space Agency (ESA) Eddington mission will search for potentially habitable planets around other stars using a 47-inch optical telescope. The mission would also study the makeup and evolution of stars.

Eddington, launched between 2008 and 2013, would carry its optical photometer mounted on a three-axis stabilized platform sitting far from Earth.

How Transits Work

From our point of view on Earth, if a planet passes in front of its parent star, it blocks a small amount of the light from that star. If such dimming of a star is caused by a planet, then the transit must be repeatable. When astronomers see three transits -- with a consistent period, duration and change in brightness -- they consider that a confirmation of the existence of a planet.

Planets even smaller than the Earth can be discovered. From change in brightness, the size of a planet can be calculated. From the period, the orbital size can be computed and the planet's temperature estimated.

In 2001, astronomers using the Hubble Space Telescope to measure the dimming of starlight during a transit of an exoplanet at the star HD 209458 in the constellation Pegasus found that the giant planet consists mostly of gas. That would make it similar to Jupiter and Saturn. Astronomers detected sodium gas in the exoplanet's atmosphere.

To detect a habitable Earth-size planet, the sensors in Kepler Space Telescope would have to pick out the dimming of starlight by 0.01 percent.

Terrestrial Planet Finder

The Terrestrial Planet Finder (TPF) would be an array of telescopes launched to Earth orbit in 2015. TPF would generate planetary pictures 100 times more detailed than those from the Hubble Space Telescope.

TPF would use "nulling," a technology from our knowledge that lightwaves from a star are something like like waves in water with crests and troughs. If a star is observed through two separate telescopes, and the light from each is brought together, the crests from one and the troughs from the other can be seen to cancel each other out. That effect could eliminate unwanted star light allowing astronomers to see if there is one or more planets around the star.

Astronomers would use TPF to build a census of Earth-sized planets up to 50 lightyears from Earth. The list would be annotated with information about their formation, development, size, temperature, amounts of gases like carbon dioxide, water vapor, ozone and methane, and suitability for life.

TPF, managed by NASA's Jet Propulsion Laboratory (JPL), will directly detect and analyze the light of planets orbiting nearby stars. At visible wavelengths, an Earth is more than 1 billion times fainter than its parent star; at infrared wavelengths, it is more than 1 million times fainter. The mission will take family portraits of stars and their orbiting planets up to 45 light years from Earth. Will use either an infrared interferometer (two or more Hubble-sized telescopes separated by 100-300 feet) or an optical coronagraph (a specially instrumented, ultra-precise telescope two to four times the size of Hubble). It will look for planets and also look for chemical signatures, such as oxygen, carbon dioxide, water vapor and ozone, of habitability, or even of life itself.
Learn more about the TPF mission

Darwin

The European Space Agency's InfraRed Space Interferometer known as Darwin is expected to launch about 2015.

Darwin would actually be an array of six small eyes forming an effective giant that would mimic a 100-yard-wide telescope. The six individual telescopes would be joined either by long arms or would each be mounted on individual spacecraft. In the former case, the rigid structure would rotate to build up the image. In the latter case, the individual spacecraft would have their own rocket motors and dance around each other to build up the image.

The telescope, looking at infrared energy rather than optical wavelengths of light, would hunt for Earth-like planets around some 300 Sun-like stars within 50 light-years of Earth.

Unlike other telescopes, Darwin would fly away from Earth to operate at a distance from the Sun between Mars and Jupiter. That position would allow Darwin's instruments to avoid dust between Earth and Mars that could obscure its view.

Next Generation Space Telescope

NGST is a powerful observatory designed to replace the Hubble Space Telescope when it retires near the end of this decade. Scheduled to launch in 2009, it will carry cameras and spectrographs senstitive to infrared radiation. Many of its proposed technologies are precursors of systems that will be used for TPF.
Learn more about the NGST mission

StarLight

A technology pathfinder. StarLight is a technology precursor to Terrestrial Planet Finder (TPF), a future mission designed to search for and characterize habitable planets around stars other than the Sun.

Previously scheduled for launch in 2006, StarLight has been directed by NASA to focus on the development of ground demonstration of technologies that support formation flying interferometry for TPF.

The main tenets of the new strategy for TPF are a robust ground technology program supporting multiple potential mission concepts. A goal of this ground technology program is to validate the technologies needed for the separated spacecraft interferometer concept (formation flying) for TPF.

StarLight will develop component and subsystem technologies needed for formation flying interferometry and will validate their performance in ground testbeds.

By moving to increasingly flight-like environments, this activity will minimize the risk of using such technologies for Terrestrial Planet Finder. These technologies might also be used for other future missions in NASA's Origins theme and Structure and Evolution of the Universe theme.
Learn more about the StarLight mission

Eclipse

Eclipse is a proposed Discovery mission to perform the first sensitive imaging study of nearby planetary systems and their evolutionary stages from formation as young stellar objects to their demise as planetary nebulae.

During a three-year science mission, Eclipse would directly detect and characterize Jupiter-class planets, zodiacal dust structures, and brown dwarf companions associated with stars in the solar neighborhood; survey the protoplanetary disks of nearby molecular clouds; and study
the dissolution of planetary systems in the winds of dying stars.

Eclipse would bring together a 1.8 meter space telescope configured for low optical scattering, a coronagraphic camera for control of diffracted light, and precision active optics for control of scattered light.

Life Finder

LF. Once we identify any habitable planets, Life Finder would fly telescopes at even larger distances to detect chemicals that actually reveal biological activities--that is, the presence of life.
Learn more about the Life Finder mission

Planet Imager

PI. If we found a planet with life, we wouldn't leave it to our imagination! To create a picture would require a number of telescopes flying in formation to achieve the power of a telescope 360 kilometers wide.
Learn more about the Planet Imager mission

Observatories on the Ground

Keck Interferometer

The world's most powerful ground-based telescope system, created by linking two 10-meter (33-foot) telescopes on Mauna Kea in Hawaii. It will study dust clouds around stars where planets may be forming and may provide the first direct detection of light from Jupiter-like planets outside our solar system. Managed by JPL. The Keck Interferometer is currently operating.
Learn more about the Keck Interferometer mission

Large Binocular Telescope Interferometer

LBTI. Two 8-meter (26-foot) telescopes on Mount Graham, Arizona will be connected. The system will be capable of imaging many faint celestial objects with 10 times the resolution of the Hubble Space Telescope. Will identify faint dust clouds around other stars that might hinder planet-finding missions. Managed by the University of Arizona, Tucson in conjunction with multiple international partners. The telescope is scheduled to begin operations in 2004.
Learn more about the LBTI mission

Palomar Testbed Interferometer

PTI. By combining light from telescopes at the Palomar Observatory, PTI takes the first crack at developing technologies that combine light coming in from distant objects in the cosmos.
Learn more about the PTI mission

NASA Origins Program Family of Missions

Support for these missions is provided by the Interferometry Science Center (ISC), a science operations and analysis service sponsored by the Origins theme and operated by the California Institute of Technology. The ISC facilitates timely and successful execution of projects that use interferometry, a key technology in the Origins Program.
Learn more about the Origins ProgramLearn more about the ISC